Coca-Cola has teamed up with Capricho Magazine to invent a pretty ingenious way of boosting the volume of your smartphone.

As you can see in the video below, the back cover of the publication (sponsored by Coca-Cola) has two carefully measured slits which means that once it’s been rolled up the two tabs align, forming a cradle.

Simply pop your smartphone in (the video uses an iPhone 4S, although we imagine it will work with most similarly sized devices) and watch/listen as the resonating factors of the rolled-up magazine naturally lift the volume of your music.

The collaboration has been made to coincide the first birthday of Coca-Cola FM, the soft drinks company’s online radio platform available in Brazil, Colombia and Costa Rica, among others.

The design itself was created by Mauro Cavalletti and the rest of the guys at Group JWT (the São Paulo branch, to be exact). We say bravo, as it’s a pretty clever and altogether simple idea for lifting the sound of your mobile device.

Particularly useful if, say, you’re at a park or on the beach with friends and you forget to bring a pair of speakers.